Results were not known when coach Sigi Schmid addressed the media later in the day.

"Michael's in today having an MRI, so they're still doing part of that," he said. "It was like a two-phased MRI because we wanted to get a really good look at what was going on there so we can make a determination."

Gspurning has started all seven games for the Sounders (5-1-1) this Major League Soccer season and has a 0.46 goals-against average -- second best in MLS.

He was replaced at halftime by 22-year-old Bryan Meredith, who made one save in his MLS debut.

If Gspurning is unable to play Saturday, when the Philadelphia Union visits CenturyLink Field, Meredith will get his first career start.

Schmid had said last week that he believes Meredith is good enough to be a starting MLS goalkeeper. And the coach figures Meredith's debut on Wednesday will only help.

"He's done it now, it's not a new situation," Schmid said. "Starting the game will be a little bit different, but his nerves are good.

"The team knows him, he's familiar with them; he's been around our team now for over a year. We're happy with that."

If Meredith moves into the starting spot, the Sounders have a couple of options for the reserve role behind him. Veteran Andrew Weber (ankle) was cleared to return to training Thursday. Also practicing with the club was MLS pool goalkeeper Steve Spangler, formerly of Oregon State. Josh Ford remains unavailable with a stress fracture in his right knee.

Goalkeeper isn't the only area where the Sounders are unsettled. Schmid said he is still deciding which field players need to be rested this weekend after playing games Saturday and Wednesday.

Adding to the uncertainty is the status of players such as midfielder Alvaro Fernandez (quad strain) and Patrick Ianni (back), who have missed recent games but who trained without apparent problems Thursday.

For now, Schmid sees no benefit in clarifying things for the Union.

"We're going to be difficult (to scout) because it makes it a little uncertain for them as to what lineup are we going to come up with," he said. "Is Fernandez ready to come back? Is (Mauro) Rosales ready to play another game? Where is (Brad) Evans at? (Fredy) Montero? (Eddie) Johnson? All those guys are guys they have to think about. We're not going to make it easy for them by giving them any answers right now."

ADDED TIME

Sounders Women will meet the University of Washington in a friendly at 7:30 p.m. today at Starfire Sports Stadium in Tukwila. The seating areas are sold out, but standing-room tickets go on sale two hours before kickoff. ... The Jet City Auxiliary has been announced as a Sounders Women supporters group. Information at http://www.JetCityAux.com.